brown butter cake with roasted rhubarb, salted caramel, and pistachio crumble

• 1/2 cup shelled, unsalted pistachios
• 40g sugar
• 40g flour
• 30g butter, cold

for the cake, heat the butter in a medium saucepan until melted. cook at a boil, stirring constantly until the milk solids turn brown and the butter starts to smell nutty. this should take 5-10 minutes. it burns quickly, so be sure to stay in front of the stove the whole time. remove from heat and pour into a bowl. stir in the vanilla (it will bubble up) and put into the freezer until half solid, about half an hour. preheat oven to 350º and grease three 6-inch cake pans. cream the chilled butter and the sugar. add in the eggs one at a time, beating after each addition. in a separate bowl, sift the flour and baking powder. fold the dry ingredients and the yogurt into the creamed mixture, alternating twice and ending with the dry. divide batter evenly into the pans and bake for 25-30 minutes, or until a toothpick inserted comes out with a few crumbs attached. let cool in pans for 5 minutes, then remove to racks to cool completely.

for the frosting, beat the cream cheese and butter until light and fluffy. add the vanilla. add the caramel. beat for 5 more minutes.

for the salted caramel, heat the butter and cream in a small saucepan over a low heat until the butter is melted and the mixture is combined. remove from heat. place the sugar and water in a large pot over high heat. cook until the mixture reaches a dark amber color (350° on a candy thermomenter), swirling the pot to allow the sugar to cook evenly. when it has reached this point (usually around 10 minutes), remove from the heat and whisk in the cream mixture – it boils up vigorously with a lot of steam, so wear an oven mitt to protect your hand. when fully combined, return to the heat for 3-5 minutes, stirring constantly, to thicken it slightly. stir in the salt and vanilla. leave to cool.

for the roasted rhubarb, preheat oven to 350º. spread the rhubarb out on a pan and sprinkle with sugar. bake for 15 minutes.

for the pistachio crumble, pulse all ingredients in a food processor until a few chunky bits remain.

to assemble, level the cakes. place one cut-side up on a cake stand and spread generously with frosting. top with a few scoops of rhubarb, a drizzle of caramel, and lots of pistachio crumbs. repeat twice, adding rosettes of frosting on the top layer if desired.